Where do you live? May be a simple question, but when companies are asking where someone lives, the answer isn’t always so easy. The physical address and the mailing address of a person can be two completely separate things. And when companies want to send direct mail, they need to ensure the message is appropriate.

Today I am going to show a Python program that I wrote that can process millions of addresses and verify if the address is a valid mailing address that matches the physical address. And how the majority of online mapping services get it wrong.